1. Field of Invention
The present invention pertains to the field of Linear Proportioners. More particularly, this invention is intended to assist an artist or drawing person to easily obtain more precise proportions by transferring dimensions from an actual scene, a photograph or any reference picture to any drawing or artist medium.
2. Description of the Related Art
Linear proportioners have been known as proportional dividers, pantographs, and proportion calipers. Proportional dividers have two similar members or legs where the distal ends of both members are pointers. The two members are connected by an adjustable pivot assembly forming a scissor-like device. When the pivot is fixed in one position, the dimension between the upper and lower pointers provide a constant ratio of those dimensions independent of the scissor opening. Therefore, dimensions on a drawing can be transferred to another drawing with the same ratio or proportion.
Pantographs are four member devices designed to permit tracing lines on a reference drawing or picture in the same plane where an object drawing is generated (usually expanded). The distal end of one member is fixed to the drawing plane with a pivot. The distal end of a different member is a stylus for tracing. The distal end of another member provides a mounting for a writing implement. The object drawing is generated with a constant ratio to the reference drawing, i.e. in proportion.
One type of proportional caliper is known as the golden proportional caliper. This device is a threaded spindle having opposite end sections with reverse threads of different pitches. The ratio of these pitches is 1 to 0.618. Where the two different threads meet there is a fixed reference pointer. At each end of the spindle there is a variable pointer. The two distances between the reference pointer and the variable pointers maintain a ratio of 1 to 0.618.
Proportional dividers and calipers are well suited for there intended design in the drafting environment. Extending the application of these devices to art environments such as canvas and easel can be awkward because of the dynamic dimension range and the physical configuration of the device. Also, in a drafting environment, an expanded or reduction of a drawing is desired using a particular ratio; it is not necessary for an Artist to utilize ratios, mathematics or actual dimensions when transferring a scene or photograph to art medium.
Other devices have been developed to overcome these and similar problems associated with . . . . Typical of the art are those devices disclosed in the following U.S. patents:
U.S. Pat. No.Inventor(s)Issue Date967,267J. C. ThompsonAug. 16, 19102,560,697J. F. JoyDec. 16, 19462,645,021M. T. DiekesJul. 14, 19532,770,884J. F. EckertNov. 20, 19563,858,324M. PadowiczJan. 7, 19754,416,063J. NestorNov. 22, 19835,154,004J. AllenOct. 13, 19927,043,849D. LegerMay 16, 2006
Of these patents, Thompson, in the '267 patent discloses a “Proportional Measuring Instrument” which can be used as a linear proportioner commonly known as a “proportional divider”. The object of the invention is to facilitate the operation of comparing linear dimensions, dividing lines proportionally, adding to a line a given proportion of that line and the instantaneous conversion linear units such as inches and meters. The configuration of this invention is similar to other proportional dividers. It consists of two similar legs connected in a scissor like fashion by an adjustable pivot assembly. Distal ends of both legs are pointers. By fixing the position of the pivot assembly, the distance between the upper leg pointers divided by the distance of the lower leg pointers will be a ratio independent of the angle between the legs. Given this constant ratio, this device can transfer linear dimensions of a drawing to a new drawing with respective proportions. In addition the '267 device has a third member connected near the ends of one set of pointers which is a measuring device for the distance between those pointers.
The '697 patent issued to Joy discloses a “Proportional Divider” configured with two similar legs by a slidable pivot assembly. Distal ends of both legs are pointers. By fixing the position of the pivot assembly, the distance between the upper leg pointers divided by the distance of the lower leg pointers will be a ratio independent of the angle between the legs. Given this constant ratio, the '697 device is provided for transferring linear dimensions of a drawing to a new expanded or reduced drawing.
The '021 patent issued to Diekes is also a “Proportional Divider” configured with two similar legs by an adjustable pivot assembly. Distal ends of both legs are pointers. By fixing the position of the pivot assembly, the distance between the upper leg pointers divided by the distance of the lower leg pointers will be a ratio independent of the angle between the legs. Given this constant ratio, the '021 device is provided for transferring linear dimensions of a drawing to a new expanded or reduced drawing.
Eckert, in the '884 patent, discloses a proportional divider configured with two similar legs and having a slidable pivot assembly. Distal ends of both legs are pointers. By fixing the position of the pivot assembly, the distance between the upper leg pointers divided by the distance of the lower leg pointers will be a ratio independent of the angle between the legs. Given this constant ratio, the '884 device is provided for transferring linear dimensions of a drawing to a new expanded or reduced drawing.
The '324 patent issued to Padowicz is a pantograph which is used to reproduce (usually enlarge) a picture or drawing by tracing lines on the reference drawing. The reference drawing and the object drawing are in the same plane where one member of a four-member apparatus is affixed to this plane via a pivot. The distal end of a second member has a stylus mounted for tracing. The distal end of a third member has a mounting for a writing implement. The four members are interconnected by pivots which maintain a constant proportion for reproduction.
The '063 patent issued to Nestor et al., and entitled, “Golden Proportion Calipers” discloses a device including a threaded spindle having opposite end sections with reverse threads of different pitches. As discussed above, the ratio of these pitches is 1 to 0.618. Where the two different threads meet there is a fixed reference pointer. At each end of the spindle there is a variable pointer. The two distances between the reference pointer and the variable pointers maintain a ratio of 1 to 0.618.
Allan, in the '004 patent, discloses a “Proportional Divider” configured with two similar legs and having a slidable pivot assembly. Distal ends of both legs are pointers. By fixing the position of the pivot assembly, the distance between the upper leg pointers divided by the distance of the lower leg pointers will be a ratio independent of the angle between the legs. Given this constant ratio, the '004 device is provided for transferring linear dimensions of a drawing to a new expanded or reduced drawing.
The '849 patent issued to Leger, and entitled “Multifunctional Caliper Instrument for the Arts,” is similar in configuration to a pantograph in that it has four members interconnected by pivots. There are four pointers at distal ends of three members. The '849 patent describes various uses for the invention. One application is a proportional divider where two of the four members are removed. The remaining two members are functionally similar to the proportional dividers above.